What has caused this?

[BuzzBravado]

Used this bike daily until covid and it was fine up until then. Recently noticed the scorpion cans both have this crumbly fibrous looking material pushing out, so much its tearing the rivets holding it in.

[BuzzBravado]

This one was scuffed in a lowside years ago, but the other can is untouched and its the same.

I think the end cap is aluminium. Didn't realise it breaks down like that.

I've dug out the original ones, which will do for now.

I have a feeling if the bike was still used daily then this wouldn't have happened. Maybe months of moisture sitting inside it? That would otherwise be burned out each morning.

[BuzzBravado]

The garage is bone dry. I was turning it over every month or so. Maybe it was going to happen anyway and its just coincidence. There isn't a great selection of exhausts for the SV/TL1000 so I might leave it standard. Not keen on £400 for more scorpions if this is how they go.